News
General Interest
Mass spectrometers help track water contaminants
October 9, 2007
By Stephanie Doster
An interdisciplinary team of University of Arizona researchers has received a three-year, $539,000 National Science Foundation grant to buy two tandem mass spectrometers that will be used to study and monitor water quality in Arizona groundwater, rivers, and streams.
The machines, each about the size of a free-standing office photocopier, will be the centerpiece of a new laboratory where researchers can develop a state-wide understanding of the distribution of micro-pollutants and emerging water contaminants and how they behave.
“One of the clear realities in Arizona is that the population is rising at a rate that is significantly higher than the rate of acquiring fresh water resources. Water re-use is going to become increasing important in the future,” said Jon Chorover, a professor of soil, water and environmental science who is leading the research. “It is imperative that we understand the potential impacts of the re-utilization process on both ecosystems and human health.”
Some pharmaceutical compounds and chemicals, like an active ingredient in birth control pills, that slip into water resources through human waste can cause abnormalities in aquatic species and have disrupted the sexual development of some amphibians and fish, Chorover said. Studies are still underway to determine if and how the chemicals affect people.
“In general, there is a large array of pharmaceutical and personal care products in the water. This is particularly important here in the desert Southwest because the hydrological cycle is very tight, and we’re often acquiring water from ground water or surface water sources that have been impacted by waste water discharge,” Chorover said.
Waste Water treatment centers do a good job of removing many contaminants, like E. coli and other bacteria, he explained, but trace contaminants tend to slip through the system only to be re-released into the environment.
The Santa Cruz River, for example, has among the highest concentration of trace contaminants in the nation, Chorover said. It courses past a waste water treatment plant in Tucson, dips into northern Mexico, and then re-enters Arizona near Nogales. Flowing through a desert landscape, it is not sufficiently diluted by natural water sources.
The grant will help scientists study and track these types of contaminants by covering the cost of two types of high-end mass spectrometers; one uses gas, the other uses liquid. Once a water sample is injected into either instrument, compounds in the sample are separated and the mass spectrometer detects and identifies them based on very precise measurements of each compound’s signature mass. The equipment can then tell researchers how much of a given compound is present.
The deans of four colleges—Agriculture and Life Sciences, Engineering, Science, and Medicine—and Leslie Tolbert, vice president for research, graduate studies, and economic development, agreed to match the grant, providing funds for additional laboratory equipment and specialized staff support.
“They all recognized the importance of a cross-disciplinary collaboration in water sustainability,” Chorover said.
The Arizona Water Institute also helped the project by providing funding for Chorover and colleagues from Arizona State University and Northern Arizona University to work with the state’s Department of Health Services to develop methods and strategies for opening the laboratory.
The project’s co-principal investigators, all from the UA, are Robert Arnold, professor of chemical and environmental engineering; Ian Pepper, director of the Environmental Research Laboratory; Vicki Wysocki, professor of chemistry and biochemistry; and A. Jay Gandolfi, associate dean for research and graduate studies and professor in the College of Pharmacy.
“We want the laboratory to represent a new model of collaborative research in which high-tech support can serve several programs,” Chorover said.
The 2,000 square-foot, state-of-the-art laboratory is expected to open on the eighth floor of the UA’s Gould-Simpson building in January 2008. Chorover said the new tandem mass spectrometers will be more accurate than those he and colleagues have been using, and the new laboratory space will allow more experimental work.
Chorover anticipates running thousands of samples through the instruments each year. In general, the lab will be open to Arizona university researchers who are studying water quality and sustainability.